This invention relates to an optical character reader, and particularly to an optical character reader which can read a postal code written or typed on a postal item.
A known optical character reader (OCR) for reading the postal code of a postal item comprises a pre-scanner and a main scanner which are spaced for a distance along the transport path of postal items. The pre-scanner coarsely scans a postal item, for example, an envelope, and generates video signals corresponding to the pattern of the postal item. According to the video signals the position of the postal code is determined through format decision. Based on the result of the format decision the main scanner scans finely the postal code. The optical character reader has a problem, however. The pre-scanner cannot distinguish the postal code from characters written or typed near the code, at the same line or the line above or below the code. It therefore often regards such characters as part of the postal code. When this happens, a correct format decision is impossible and the envelope will be rejected. The optical character reader has but a poor reading accuracy.